Hi Zhi,
Thank you for all the detailed information. I have some good news. The wrong band index is just a formatting error and will not impact any of the results of your calculation. In amset run the VBM and CBM band indices run from 1 to NBANDS, whereas in amset deform read the printed indices of the CBM and VBM run from 0 to NBANDS - 1. I just forgot to add +1 in the print statement.
I will push a fix to amset later today.
I would like to investigate why amset deform read -s N ... command fails. Would you be willing to send me your vasprun.xml file and I will do some tests. Feel free to email it to me if you prefer.
Best,
Alex